Pages: [1]   Go Down
Author Topic: Interfacing a large 4" 7 segment LED display  (Read 772 times)
0 Members and 1 Guest are viewing this topic.
Holland
Offline Offline
Newbie
*
Karma: 0
Posts: 1
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi all,

I'm trying to interface a large Kingbright 4" LED 7-segment display with my Arduino Duemillanove.  Electronics design is not my trade, and I'm having a hard time deciphering the data sheet.  I can't even find the required voltages smiley-roll-sweat

If someone can come up with a schematic to connect it to an Arduino I would be most grateful.

Datasheet: http://www.us.kingbright.com/images/catalog/SPEC/SA40-19EWA.pdf

Many thanks,
Walter
Logged

Offline Offline
Jr. Member
**
Karma: 0
Posts: 57
Nokia 6100 LCD Library
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Ummm... your datasheet clearly says 8V typical Forward Voltage drop, max fwd current per segment of 60mA etc. You shd probably stay closer to 30mA per leg. You should be able power it through a 9V battery with current limiting resistors.

The key thing to note is you'll need to use arduino to "switch" segments on & off since Arduino Uno digital pins can't give u more than 5V  - the simplest way (and the messiest) would be to use transistor switches for each segment http://en.wikipedia.org/wiki/Transistor#Transistor_as_a_switch. I'm sure if you want to get more sophisticated u can Google on MOSFETs etc :-)

PS: Just noted 1 more complexity - your decimal point - marked DP in the datasheet takes only 4V and not 8V. I think the device would have been better designed if it took only 1 supply voltage - but if you don't need it, simply don't connect the decimal point to your circuit :-)

« Last Edit: April 12, 2012, 06:45:09 am by srinathdevelopment » Logged

Ardgrafix6100 - A fast, full-featured Arduino graphics driver for Nokia 6100 LCDs http://code.google.com/p/ardgrafix6100/

Pages: [1]   Go Up
Jump to: